The present invention relates to a process for fleshing skins.
In the tanning or tawery industry, it is known that fleshing is a delicate and unpleasant operation. The complete elimination of flesh, notably from pickled sheep skins originating in the southern hemisphere, is often laborious and it generally causes, when it is incomplete, a retraction of the skin leading to a 2 to 5% reduction in the finished surface area. Moreover, badly fleshed skins are sometimes difficult to subsequently degrease. In order to obviate these inconveniences, the Applicant has discovered a new skin fleshing process characterized by the fact that the skins to be fleshed are treated with a silica sol then the standard fleshing operations are carried out on the skins treated in this way. The silica sol can be used, for example, at a rate of 0.2% to 3% by weight relative to the weight of skins in this state.
By silica sol is meant, a commercial silica sol containing, by weight, preferably from 30 to 50% silica in a non-agglomerated particle state, with an average diameter of 9 to 100 nanometers, advantageously from 9 to 50 nanometers. The silica sol is advantageously employed in aqueous solution.